The present invention relates to a small animal rearing apparatus provided with a washing system and used for rearing small experimental animals, such as rats or mice. More particularly, the present invention relates to improvements in the floor boards of rearing sections, and a washing system provided with washing nozzles.
FIGS. 5 and 6 show a small animal rearing apparatus 1 for rearing small experimental animals, such as rats or mice, disclosed in JP-B-61-59083. This small animal rearing apparatus 1 has a frame 2 of a rectangular shape formed by assembling angle bars. Casters 3 are attached to the lower end of the frame 2. A space defined by the frame 2 is divided into a plurality of vertically arranged rearing sections 4 by angle bars. Floor boards 5 are fixedly supported on the frame 2 for defining the rearing sections 4, respectively. The floor boards 5 are sloped down toward the front (toward the right as viewed in FIG. 6) to facilitate cleaning the rearing sections 4. A rear edge portion (a left edge portion as viewed in FIG. 6) of each floor board 5 is bent up to form a raised rim 6 as shown in FIG. 7. A scraper plate 7 for scraping dirt, such as small animals"" excrements, off the floor board 5, and a spray nozzle 8 for spraying washing water are supported for movement along the raised rim 6 of each floor board 5. The scraper plates 7 and the spray nozzle 8 are moved along the raised rims 6 of the floor boards 5 in directions along the length of the frame 2 (longitudinal directions). A proximal end part of each scraper plate 7 is joined to a support member 11 supporting the spray nozzle 8 by a hinge 10. Dirt scraped off the floor boards 5 by the scraper plates 7 and washing water sprayed by the spray nozzles 8 flow through drain pipes 9 into a sump 12 or into a sewer. A plurality of rearing cases 13 accommodating small animals are placed in longitudinal arrangement in each rearing section 4.
The floor board 5 of the rearing section 4 has the raised rim 6 on the side of the spray nozzle 8 and the spray nozzle 8 is disposed above the raised rim 6, and hence washing water is sprayed in a direction inclined at an angle to the upper surface of the floor board 5. Since the floor board 5 has the raised rim 6, the spray nozzle 8 and the scraper plate 7 are on different levels, respectively, and the scraper plate 7 needs to be connected to the nozzle 8 by the hinge 10. Consequently, washing water cannot be sprayed on a rear region of the upper surface of the floor board 5 near the raised rim 6 as shown in FIG. 8 and the rear region of the upper surface of the floor board 5 cannot be washed. In some cases, wash water is splashed on the small animals by the scraper plates 7 and the floor boards 5 as shown in FIG. 9. Since the spray nozzle 8 has the shape of a straight pipe and is disposed above the raised rim 6, the rear region of the upper surface of the floor board 5 is in the dead space of the spray nozzle 8, and dirt adhering to the rear region cannot satisfactorily be washed away. The hinge 10 is liable to break and obstruct cleaning operation. The scraper plate 7 needs to be formed in a relatively great width to enable the scraper plate 7 to slide smoothly along the upper surface of the floor board 5. However, the wide scraper plate 7 sometimes sticks to the floor board 5 and becomes immovable if a film of water is formed between the scraper plate 7 and the upper surface of the floor board 5.
Since the floor boards 5 are fixedly supported on the frame 2, the rearing apparatus 1 cannot be easily assembled and work to remove the floor boards 5 from the frame 2 for maintenance and thorough cleaning takes much time. Since the floor boards 5 are mounted on stainless steel plates, spaces between the floor board 5 and the stainless steel plates provide suitable nests of insects. Since those spaces are poorly ventilated and the animal rearing room is kept at temperatures around 22xc2x0 C., bacteria and mold are liable to propagate therein. Moreover, it is difficult to warp the floor boards 5 so as to conform to the shapes of the scraper plates 7 when the scraper plates 7 are moved along the upper surface of the floor boards 5 because the floor boards 5 are mounted on the stainless steel plate.
The present invention has been made to solve those problems in the conventional small animal rearing apparatus and it is therefore an object of the present invention to provide a small animal rearing apparatus provided with floor boards capable of being satisfactorily washed and maintained and of easily warping so as to conform to t he shape of scraper plates.
According to the present invention, a small animal rearing apparatus comprises a frame of a rectangular shape, a rearing unit having a plurality of rearing sections formed in vertical arrangement and provided respectively with floor boards sloping downward toward the front, and spray nozzles disposed respectively on the levels of the floor boards to spray washing water from higher rear ends of the floor boards toward lower front ends of the floor boards along the upper surfaces of the floor boards, respectively, in which the higher rear end of the floor board of each rearing section underlying the spray nozzle is free from any raised part.
Preferably, the floor boards of the rearing sections are detachably attached to floor board support frames supported on the frame. Each floor board has a downward rear rim formed by bending a rear edge portion thereof downward, and the floor board is held in place on the floor board support frame with the downward rear rim thereof engaged with a member of the floor board support frame. Preferably, each spray nozzle has a bellows-shaped body.
The above and other objects, features and advantages of the present invention will become more apparent from the following description taken in connection with the accompanying drawings.